CN112594076A - Diesel engine minimum intake preheating power design method with low-temperature adaptability - Google Patents

Diesel engine minimum intake preheating power design method with low-temperature adaptability Download PDF

Info

Publication number
CN112594076A
CN112594076A CN202011471866.2A CN202011471866A CN112594076A CN 112594076 A CN112594076 A CN 112594076A CN 202011471866 A CN202011471866 A CN 202011471866A CN 112594076 A CN112594076 A CN 112594076A
Authority
CN
China
Prior art keywords
air
temperature
diesel engine
res
minimum
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202011471866.2A
Other languages
Chinese (zh)
Other versions
CN112594076B (en
Inventor
黎一锴
史中杰
王东方
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Institute of Technology BIT
Original Assignee
Beijing Institute of Technology BIT
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing Institute of Technology BIT filed Critical Beijing Institute of Technology BIT
Priority to CN202011471866.2A priority Critical patent/CN112594076B/en
Publication of CN112594076A publication Critical patent/CN112594076A/en
Application granted granted Critical
Publication of CN112594076B publication Critical patent/CN112594076B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/04—Introducing corrections for particular operating conditions
    • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
    • F02D41/062—Introducing corrections for particular operating conditions for engine starting or warming up for starting
    • F02D41/064—Introducing corrections for particular operating conditions for engine starting or warming up for starting at cold start
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/04—Introducing corrections for particular operating conditions
    • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
    • F02D41/068—Introducing corrections for particular operating conditions for engine starting or warming up for warming-up
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M31/00—Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture
    • F02M31/02—Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture for heating
    • F02M31/04—Apparatus for thermally treating combustion-air, fuel, or fuel-air mixture for heating combustion-air or fuel-air mixture
    • F02M31/042—Combustion air

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Abstract

The invention discloses a method for designing minimum intake preheating power of a diesel engine with low-temperature adaptability, which comprises the following steps: step one, taking a critical ignition condition as a critical state of compression ending in a cylinder of the diesel engine, and calculating the lowest compression initial point temperature of the diesel engine; determining the lowest preheated intake temperature at the start-up rotation speed and the Ramp rotation speed of the diesel engine; calculating the minimum preheating power of the air inlet preheating device according to the initial flow, the initial temperature, the lowest preheated air inlet temperature and the constant pressure specific heat of the air, and obtaining the minimum preheating power of the air inlet preheating device of the diesel engine at different initial temperatures by changing the initial temperature; the invention can realize the self-adaptive adjustment of the minimum intake preheating power of the intake preheating device along with the rotating speed of the diesel engine and the initial temperature of air in the starting process of the diesel engine, improves the defects of the existing design method and is beneficial to the improvement of the environmental adaptability of the diesel engine.

Description

Diesel engine minimum intake preheating power design method with low-temperature adaptability
Technical Field
The invention belongs to the technical field of diesel engines, and particularly relates to a method for designing minimum intake preheating power of a diesel engine with low-temperature adaptability.
Background
The diesel engine has low rotating speed, large air leakage and high heat dissipation during the starting process, so that the temperature and density at the end of compression in a cylinder are reduced, the ignition and stagnation period of diesel oil spray is increased, and even the critical phenomena of partial spontaneous combustion or fire catching and the like occur. Diesel spray misfire is the root cause of poor cold start performance of diesel engines. The basic characteristics of climate and terrain in China are that China has broad breadth, large temperature difference between south and north and large difference between east and west altitudes. The lowest temperature of the north juncture river in China can reach-52.3 ℃ in winter. In a low-temperature environment, the starting resistance moment is sharply increased due to the increase of the viscosity of the engine oil, and a serious insufficient power problem is faced in the starting process of the diesel engine. And the self-ignition of the diesel spray under the low-temperature environment is also increasingly difficult, which leads to the worse cold starting performance of the diesel engine.
The air inlet of the diesel engine is preheated, the air temperature is increased and then the air enters the engine, the final compression temperature in the cylinder can be effectively increased, and the method is an important means for solving the problem of poor cold starting performance of the diesel engine in a low-temperature environment. Since the exhaust gas turbocharger is not in use in the cold start phase, only the fresh air heated by the intake air preheating device directly enters the diesel engine cylinder. In the conventional electrically heated air inlet preheating device (or flame preheating) of the diesel engine, the preheating power (or oil supply rate) is constant, and the air inlet preheating power is not changed along with the change of the rotating speed and the atmospheric temperature. The intake air preheating power (or the fuel supply rate) is determined under the condition that the intake air preheating power demand is the largest, and the preheating power surplus is caused under other conditions. The diesel engine using the existing intake preheating design method has the intake preheating power which does not change along with the change of the rotating speed and does not have the environmental adaptability which changes along with the change of the atmospheric environmental temperature.
In summary, the existing intake preheating design method cannot determine the intake preheating power with low-temperature environmental adaptability in the starting process of the diesel engine. In order to improve the cold starting performance of the diesel engine in a low-temperature environment, a new design method of the minimum intake preheating power of the diesel engine with low-temperature adaptability is urgently needed.
Disclosure of Invention
In view of the above, the invention provides a method for designing the minimum intake preheating power of a diesel engine with low-temperature adaptability, which can realize the self-adaptive adjustment of the minimum intake preheating power of an intake preheating device along with the rotation speed of the diesel engine and the initial temperature of air in the starting process of the diesel engine, improve the defects of the existing design method, and is beneficial to the improvement of the environmental adaptability of the diesel engine.
The invention is realized by the following technical scheme:
a method for designing minimum intake preheating power of a diesel engine with low-temperature adaptability comprises the following specific steps:
step one, taking a critical ignition condition as a critical state of compression ending in a cylinder of the diesel engine, and calculating the lowest compression initial point temperature T of the diesel engine1-min，The calculation formula is as follows;
Figure BDA0002836119940000021
where ε is the compression ratio, k is the adiabatic exponent, PinAt atmospheric pressure, f is 1-3.68 n-0.5N is the diesel engine speed;
step two, determining the lowest pre-heating intake temperature T under the start-up rotation speed and the Ramp rotation speed of the diesel enginein-min；
Figure BDA0002836119940000022
Wherein, Tin-min-startThe minimum temperature of the preheated intake air at the starting and spraying rotating speed of the diesel engine is obtained; t isin-min-rampIs the minimum temperature after preheating of the inlet air at the Ramp speed of the diesel engine, LHV is the low heating value of the fuel, cvThe specific heat is constant volume and specific heat of air;
step three, according to the initial flow m of the airairInitial temperature TairMinimum preheated inlet temperature Tin-minAnd specific heat at constant pressure cpCalculating the minimum preheating power P of the intake preheating deviceheat-minThe calculation formula is as follows:
Pheat-min＝mairCp(Tin-min-Tair) Formula (12)
By varying the initial temperature TairObtaining different initial temperatures TairMinimum preheating power of an air inlet preheating device of the lower diesel engine.
Further, in the step one, the lowest compression initial point temperature T of the diesel engine is calculated1-minThe method comprises the following steps:
step 1, determining critical ignition temperature T of diesel spraycAnd critical ignition density ρcThe relationship between, the relationship is as follows:
Figure BDA0002836119940000023
step 2, according to the inlet air temperature T of the diesel engine1And the pressure of intake air P1Compression ratio epsilon, gas constant RgCalculating the actual compression end temperature T of the diesel engine according to the adiabatic index k and the rotating speed n of the diesel engine2And actual compression end density ρ2；
Figure BDA0002836119940000024
Figure BDA0002836119940000025
Step 3, taking the critical ignition condition as the critical state of the compression end in the cylinder of the diesel engine, namely T2＝Tc，ρ2＝ρcThe simultaneous expression (1) and the expression (2) can be obtained,
Figure BDA0002836119940000031
thus, T1-min＝T1Thus, formula (3) can be obtained.
Further, in step twoDetermining the lowest pre-heating intake temperature T at the start-up rotation speed and the Ramp rotation speed of the diesel enginein-minThe method comprises the following steps:
(1) lowest temperature T after preheating inlet air at starting speed of diesel enginein-min-startEqual to the lowest compression starting point temperature T of the diesel engine1-minNamely:
Tin-min-start＝T1-minformula (4)
(2) Calculating the minimum temperature T after preheating the inlet air at the Ramp rotating speed of the diesel enginein-min-ramp：
Step 2-1, the compression initial point temperature of the mixture of the residual waste gas and the preheated air is TmixedAnd a compression onset density of ρmixed(ii) a According to the lower heating value LHV of the fuel and the constant specific heat c of the airvCalculating a residual exhaust gas temperature T of residual exhaust gas generated after combustion in a combustion chamber of a diesel engineresAnd residual exhaust gas density ρresThe calculation formula is as follows:
Figure BDA0002836119940000032
Figure BDA0002836119940000033
wherein, T3The combustion end temperature; rho3Density is at the end of combustion;
lambda is the constant volume pressure ratio of the Otto cycle,
Figure BDA0002836119940000034
sigma is the equivalent expansion ratio of the otto cycle,
Figure BDA0002836119940000035
step 2-2, obtaining T according to step 2-1resAnd ρresCalculating the single-cylinder displacement V of the diesel enginehAir mass mair-cycleVolume V of combustion chambercMass m of residual exhaust gasresAnd the total mass m after mixingair-cycle+mres；
mres＝Vcρres
mair-cycle＝Vhρin
mair-cycle+mres＝(Vh+Vc)ρmixedFormula (6)
Step 2-3, enabling the single-cylinder displacement V preheated by the minimum intake preheating powerhThe lowest preheated intake air temperature is Tin-minAir and combustion chamber volume VcTemperature of TresThe residual waste gas is subjected to constant-pressure adiabatic mixing, so that:
mresCV-resTres+mair-cycleCV-airTin-min＝(mres+mair-cycle)CV-mixedTmixedformula (7)
Wherein, cV-resIs the constant specific heat of the residual waste gas, cV-airIs the constant specific heat of air, cV-mixedIs the constant specific heat of the gas after the residual waste gas and the air are mixed, and cV-res＝cV-air＝cV-mixed；
Step 2-4, simultaneous formula (5) -formula (7), the compression starting point temperature T of the mixed residual waste gas and preheated air can be obtainedmixedComprises the following steps:
Figure BDA0002836119940000041
step 2-5, due to Tmixed＝T1-minAre equal, therefore T of formula (3)1-minThe expression (c) is substituted into the formula (8), and the lowest preheated intake air temperature T can be calculatedin-minI.e. the lowest pre-heated intake air temperature T during the Ramp speed of the diesel enginein-min-rampNamely:
Figure BDA0002836119940000042
further, the initial flow rate m of air in step threeairThe calculation method of (2) is as follows:
according to the number tau of cylinders and the single-cylinder discharge V of the diesel enginehInflation efficiency eta and atmospheric pressure PinMinimum preheated inlet temperature Tin-minAnd the rotating speed n of the diesel engine, and calculating the initial flow of the air entering the air inlet preheating device as mairThe calculation formula is as follows:
Figure BDA0002836119940000043
further, in step 1, the critical ignition temperature T of the diesel spray is determinedcAnd critical ignition density ρcThe relationship between the following was tested:
step 1-1, based on a diesel oil spraying test, under the premise that the density of background air is a set value A and is kept constant, the temperature of the background air is gradually reduced to obtain the critical ignition temperature T of the diesel oil sprayingc1And its corresponding critical ignition density rhoc1；
Step 1-2, changing the background air density, gradually reducing the temperature of the background air under the premise that the background air density is a set value B and is kept constant, and obtaining the critical ignition temperature T of the diesel sprayc2And its corresponding critical ignition density rhoc2；
Step 1-3, repeating step 1-2 to obtain corresponding critical ignition temperature T under different background air densitiescAnd critical ignition density ρcTo obtain the critical ignition temperature TcWith respect to critical ignition density ρcIs a fitting relation in the form of a cubic polynomial, namely formula (1).
Has the advantages that: the invention can change the minimum preheating power of the diesel engine air inlet preheating device along with the rotating speed of the diesel engine and the initial temperature of air, and can self-adaptively adjust the minimum air inlet preheating power of the air inlet preheating device, so that the diesel engine has low-temperature adaptability, and the cold starting performance and the environmental adaptability of the diesel engine are improved.
Drawings
FIG. 1 is a schematic diagram of the operation of the present invention;
FIG. 2 is a computational schematic of the present invention;
FIG. 3 is a graph of ignition of a diesel spray at different temperatures;
FIG. 4 is a graph showing a fitting relationship between a critical ignition temperature and a critical ignition density;
FIG. 5 is a graph of preheat power versus initial temperature at start-up speed;
fig. 6 is a graph of the preheating power at Ramp speed as a function of the initial temperature.
Detailed Description
The invention is described in detail below by way of example with reference to the accompanying drawings.
The embodiment provides a method for designing minimum intake preheating power of a diesel engine with low-temperature adaptability, which comprises the following specific steps:
referring to FIGS. 1-2, the initial flow of air into the inlet preheater is given by mairInitial pressure of Pair(i.e., atmospheric pressure) and an initial temperature TairInitial density is rhoair(ii) a After the air is preheated in the air inlet preheating device, the air pressure of the discharged air is Pin(i.e. atmospheric pressure) and an air temperature TinAir density is rhoin(ii) a The discharged air enters the diesel engine to provide power for starting the diesel engine, the air inlet pressure of the diesel engine is P1 (namely atmospheric pressure), and the air inlet temperature is T1(ii) a Wherein, Pair＝Pin＝P1＝1 bar，ρin＜ρair，Tin＞Tair(ii) a When the air is preheated in the intake air preheating device with the minimum intake air preheating power, the temperature of the discharged air is Tin-minI.e. the minimum preheated inlet temperature, at which point the minimum inlet temperature T of the diesel engine is at the start-up speed of the diesel engine1-minAnd the lowest preheated intake temperature Tin-minEqual, said T1-minNamely the most important diesel engineA low compression onset temperature; at the Ramp speed of the diesel engine (i.e. during the speed Ramp-up period), the lowest compression start temperature T of the diesel engine1-minCompression onset temperature T after mixing with residual exhaust gas and airmixedEqual;
step one, determining the critical ignition temperature T of diesel spray through testscAnd critical ignition density ρcThe relationship between, the relationship is as follows:
Figure BDA0002836119940000051
step two, determining an actual compression stroke calculation formula in the starting process of the diesel engine, namely according to the air inlet temperature T of the diesel engine1And the pressure of intake air P1Compression ratio epsilon, gas constant RgCalculating the actual compression end temperature T of the diesel engine according to the adiabatic index k and the rotating speed n of the diesel engine2And actual compression end density ρ2；
Figure BDA0002836119940000061
Figure BDA0002836119940000062
f＝1-3.68*n-0.5Formula (2)
Wherein, P2The pressure is the actual compression final pressure of the diesel engine;
step three, taking the critical ignition condition as the critical state (namely T) of the compression end in the cylinder of the diesel engine2＝Tc，ρ2＝ρc) Calculating the lowest compression initial point temperature T of the diesel engine by simultaneous formula (1) and formula (2)1-minAt this time, T1-min＝T1；
Figure BDA0002836119940000063
Step four, determining the lowest preheated intake temperature T under two working conditionsin-min；
(1) The first working condition is as follows: determining the minimum temperature T after preheating of inlet air at the start-up rotation speed of the diesel enginein-min-startIn the process, combustion does not occur in a combustion chamber of the diesel engine, so that residual waste gas generated after combustion is not considered;
lowest temperature T after preheating inlet air at starting speed of diesel enginein-min-startEqual to the lowest compression starting point temperature T of the diesel engine1-minNamely:
Tin-min-start＝T1-minformula (4)
(2) The second working condition is as follows: calculating the Ram of a diesel enginepIntake air pre-heating minimum temperature T at rotation speed (i.e. during rotation speed increase)in-min-rampIn the process, combustion occurs in a combustion chamber of the diesel engine, so that residual exhaust gas generated after the combustion is considered;
step 4-1, the internal circulation of the diesel engine cylinder in the rotation speed rising period of the diesel engine is made to be an Otto circulation, and the temperature of the compression starting point after the residual waste gas and the preheated air are mixed is TmixedAnd a compression onset density of ρmixed(ii) a The expansion line of the Otto cycle is prolonged until the expansion line intersects with the air inlet pressure line, which is equivalent to the expansion of the gas in the cylinder of the diesel engine to the air pressure Pin(i.e. atmospheric pressure) according to the lower heating value LHV of the fuel and the constant specific heat capacity c of the airvCalculating a residual exhaust gas temperature T of residual exhaust gas generated after combustion in a combustion chamber of a diesel engineresAnd residual exhaust gas density ρresThe calculation formula is as follows:
Figure BDA0002836119940000064
Figure BDA0002836119940000065
wherein, T3The combustion end temperature; rho3Density is at the end of combustion;
lambda is the constant volume pressure ratio of the Otto cycle,
Figure BDA0002836119940000066
sigma is the equivalent expansion ratio of the otto cycle,
Figure BDA0002836119940000071
step 4-2, obtaining T according to step 4-1resAnd ρresCalculating the single-cylinder displacement V of the diesel enginehAir mass mair-cycleVolume V of combustion chambercMass m of residual exhaust gasresAnd the total mass m after mixingair-cycle+mres；
mres＝Vcρres
mair-cycle＝Vhρin
mair-cycle+mres＝(Vh+Vc)ρmixedFormula (6)
Step 4-3, the volume preheated by the minimum intake preheating power is set as Vh(Single-cylinder discharge capacity) and the lowest preheated intake air temperature is Tin-minAir and volume of Vc(volume of combustion chamber) temperature TresThe residual waste gas is subjected to constant-pressure adiabatic mixing, so that:
mresCV-resTres+mair-cycleCV-airTin-min＝(mres+mair-cycle)CV-mixedTmixedformula (7)
Wherein, cV-resIs the constant specific heat of the residual waste gas, cV-airIs the constant specific heat of air, cV-mixedIs the constant specific heat of the gas after the residual waste gas and the air are mixed, and cV-res＝cV-air＝cV-mixed；
Step 4-4, simultaneous formula (5) -formula (7), the compression starting point temperature T of the mixed residual waste gas and preheated air can be obtainedmixedComprises the following steps:
Figure BDA0002836119940000072
step 4-5, due to TmixedAnd T in step three1-minAre equal, therefore T of formula (3)1-minThe expression (c) is substituted into the formula (8), and the lowest preheated intake air temperature T can be calculatedin-min，I.e. the lowest pre-heated inlet air temperature T during Ramp speed of the diesel enginein-min-rampNamely:
Figure BDA0002836119940000073
to sum up, the lowest post-warm-up intake air temperature T after the intake air pre-heating device is pre-heated with the minimum intake air pre-heating powerin-minThe expression of (a) is as follows:
Figure BDA0002836119940000081
step five, according to the number tau of cylinders and the single-cylinder displacement V of the diesel enginehCharging efficiency eta and air pressure P after the intake air preheating device is preheated with minimum intake air preheating powerinMinimum preheated inlet temperature Tin-minAnd the rotating speed n of the diesel engine, and calculating the initial flow of the air entering the air inlet preheating device as mairThe calculation formula is as follows:
Figure BDA0002836119940000082
step six, according to the initial flow mairInitial temperature TairMinimum preheated inlet temperature Tin-minAnd specific heat at constant pressure cpCalculating the minimum preheating power P of the intake preheating deviceheat-mminThe calculation formula is as follows:
Pheat-min＝mairCp(Tin-min-Tair) Formula (12)
The formula (10) and the formula (11) are substituted into the formula (12) to obtain,
Figure BDA0002836119940000083
at this point, the basic parameters of the diesel engine are input, and the initial temperature T is adjustedairThe minimum preheating power of the air inlet preheating device of the diesel engine can be obtained along with the rotating speed and the initial temperature T of the diesel engineairThe Map is changed, and the design of the minimum intake preheating power of the diesel engine with low-temperature adaptability is completed;
in this embodiment, the basic parameters of the diesel engine are: the start-up speed of the diesel engine is 200rpm, the Ramp speed is 200rpm to 800rpm, the compression ratio epsilon is 13.8, and the single-cylinder displacement V ishWhen the fuel temperature is 2L, the charging efficiency eta is 0.8 and the lower heating value LHV of the fuel is 43kJ/kg, respectively calculating different initial temperatures TairThe minimum preheating power at the spray start rotation speed and the minimum preheating power at the Ramp rotation speed, as shown in fig. 5 and 6.
Wherein the critical ignition temperature T of the diesel spray is determined in step onecAnd critical ignition density ρcThe relationship between the following was tested:
step 1-1, based on a diesel oil spraying test, under the premise that the density of background air is a set value A and is kept constant, the temperature of the background air is gradually reduced to obtain the critical ignition temperature T of the diesel oil sprayingc1And its corresponding critical ignition density rhoc1(ii) a As shown in FIG. 3, the critical ignition temperature T at this densityc1Is 720K;
step 1-2, changing the background air density, gradually reducing the temperature of the background air under the premise that the background air density is a set value B and is kept constant, and obtaining the critical ignition temperature T of the diesel sprayc2And its corresponding critical ignition density rhoc2；
Step 1-3, repeating step 1-2 to obtain corresponding critical ignition temperature T under different background air densitiescAnd critical ignition density ρcTo obtain the critical ignition temperature TcWith respect to critical ignition density ρcAs shown in fig. 4; the fitting relation is as follows:
Figure BDA0002836119940000091
in summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (5)

1. A method for designing minimum intake preheating power of a diesel engine with low-temperature adaptability is characterized by comprising the following specific steps:
step one, taking a critical ignition condition as a critical state of compression ending in a cylinder of the diesel engine, and calculating the lowest compression initial point temperature T of the diesel engine1-minThe calculation formula is as follows;
Figure FDA0002836119930000011
where ε is the compression ratio, k is the adiabatic exponent, PinAt atmospheric pressure, f is 1-3.68 n-0.5N is the diesel engine speed;
step two, determining the lowest pre-heating intake temperature T under the start-up rotation speed and the Ramp rotation speed of the diesel enginein-min；
Figure FDA0002836119930000012
Wherein, Tin-min-startThe minimum temperature of the preheated intake air at the starting and spraying rotating speed of the diesel engine is obtained; t isin-min-rampIs the minimum temperature after preheating of the inlet air at the Ramp speed of the diesel engine, LHV is the low heating value of the fuel, cvThe specific heat is constant volume and specific heat of air;
step three, according to the initial flow m of the airairInitial temperature TairMinimum preheated inlet temperature Tin-minAnd specific heat at constant pressure cpCalculating the minimum preheating power P of the intake preheating deviceheat-minThe calculation formula is as follows:
Pheat-min＝maircp(Tin-min-Tair) Formula (12)
By varying the initial temperature TairObtaining different initial temperatures TairMinimum preheating power of an air inlet preheating device of the lower diesel engine.
2. The method for designing diesel engine minimum intake preheating power with low temperature adaptability according to claim 1, characterized in that in step one, the diesel engine minimum compression start point temperature T is calculated1-minThe method comprises the following steps:
step 1, determining critical ignition temperature T of diesel spraycAnd critical ignition density ρcThe relationship between, the relationship is as follows:
Figure FDA0002836119930000013
step 2, according to the inlet air temperature T of the diesel engine1And the pressure of intake air P1Compression ratio epsilon, gas constant RgCalculating the actual compression end temperature T of the diesel engine according to the adiabatic index k and the rotating speed n of the diesel engine2And actual compression end density ρ2；
Figure FDA0002836119930000014
Figure FDA0002836119930000015
Step 3, taking the critical ignition condition as the critical state of the compression end in the cylinder of the diesel engine, namely T2＝Tc，ρ2＝ρcThe simultaneous expression (1) and the expression (2) can be obtained,
Figure FDA0002836119930000021
thus, T1-min＝T1Thus, formula (3) can be obtained.
3. The method for designing minimum intake preheating power of a diesel engine with low temperature adaptability according to claim 1, wherein in the second step, the minimum preheating intake temperature T at the start-up rotation speed and the Ramp rotation speed of the diesel engine is determinedin-minThe method comprises the following steps:
(1) lowest temperature T after preheating inlet air at starting speed of diesel enginein-min-startEqual to the lowest compression starting point temperature T of the diesel engine1-minNamely:
Tin-min-start＝T1-minformula (4)
(2) Calculating the minimum temperature T after preheating the inlet air at the Ramp rotating speed of the diesel enginein-min-ramp：
Step 2-1, the compression initial point temperature of the mixture of the residual waste gas and the preheated air is TmixedAnd a compression onset density of ρmixed(ii) a According to the lower heating value LHV of the fuel and the constant specific heat c of the airvCalculating a residual exhaust gas temperature T of residual exhaust gas generated after combustion in a combustion chamber of a diesel engineresAnd residual exhaust gas density ρresThe calculation formula is as follows:
Figure FDA0002836119930000022
Figure FDA0002836119930000023
wherein, T3The combustion end temperature; rho3Density is at the end of combustion;
lambda is the constant volume pressure ratio of the Otto cycle,
Figure FDA0002836119930000024
sigma is the equivalent expansion ratio of the otto cycle,
Figure FDA0002836119930000025
step 2-2, obtaining T according to step 2-1resAnd ρresCalculating the single-cylinder displacement V of the diesel enginehAir mass mair-cycleVolume V of combustion chambercMass m of residual exhaust gasresAnd the total mass m after mixingair-cycle+mres；
mres＝Vcρres
mair-cycle＝Vhρin
mair-cycle+mres＝(Vh+Vc)ρmixedFormula (6)
Step 2-3, enabling the single-cylinder displacement V preheated by the minimum intake preheating powerhThe lowest preheated intake air temperature is Tin-minAir and combustion chamber volume VcTemperature of TresThe residual waste gas is subjected to constant-pressure adiabatic mixing, so that:
mrescV-resTres+mair-cyclecV-airTin-min＝(mres+mair-cycle)cV-mixedTmixedformula (7)
Wherein, cV-resIs the constant specific heat of the residual waste gas, cV-airIs the constant specific heat of air, cV-mixedIs the constant specific heat of the gas after the residual waste gas and the air are mixed, and cV-res＝cV-air＝cV-mixed；
Step 2-4, simultaneous formula (5) -formula (7), the compression starting point temperature T of the mixed residual waste gas and preheated air can be obtainedmixedComprises the following steps:
Figure FDA0002836119930000031
step 2-5, due to Tmixed＝T1-minAre equal, therefore T of formula (3)1-minThe expression (c) is substituted into the formula (8), and the lowest preheated intake air temperature T can be calculatedin-minI.e. the lowest pre-heated intake air temperature T during the Ramp speed of the diesel enginein-min-rampNamely:
Figure FDA0002836119930000032
4. the method for designing diesel engine minimum intake preheating power with low temperature adaptability according to claim 1, characterized in that the initial flow rate m of air in step threeairThe calculation method of (2) is as follows:
according to the number tau of cylinders and the single-cylinder discharge V of the diesel enginehInflation efficiency eta and atmospheric pressure PinMinimum preheated inlet temperature Tin-minAnd the rotating speed n of the diesel engine, and calculating the initial flow of the air entering the air inlet preheating device as mairThe calculation formula is as follows:
Figure FDA0002836119930000033
5. the method for designing minimum intake preheating power of diesel engine with low temperature adaptability according to claim 2, characterized in that in step 1, the critical ignition temperature T of diesel spray is determinedcAnd critical ignition density ρcThe relationship between the following was tested:
step 1-1, based on a diesel oil spraying test, under the premise that the density of background air is a set value A and is kept constant, the temperature of the background air is gradually reduced to obtain the critical ignition temperature T of the diesel oil sprayingc1And its corresponding critical ignition density rhoc1；
Step 1-2, changing the background air density, gradually reducing the temperature of the background air under the premise that the background air density is a set value B and is kept constant, and obtaining the critical ignition temperature T of the diesel sprayc2And its corresponding critical ignition density rhoc2；
Step 1-3, repeating step 1-2 to obtain corresponding critical ignition temperature T under different background air densitiescAnd critical ignition density ρcTo obtain the critical ignition temperature TcWith respect to critical ignition density ρcIs a fitting relation in the form of a cubic polynomial, namely formula (1).
CN202011471866.2A 2020-12-15 2020-12-15 Diesel engine minimum intake preheating power design method with low-temperature adaptability Active CN112594076B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011471866.2A CN112594076B (en) 2020-12-15 2020-12-15 Diesel engine minimum intake preheating power design method with low-temperature adaptability

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011471866.2A CN112594076B (en) 2020-12-15 2020-12-15 Diesel engine minimum intake preheating power design method with low-temperature adaptability

Publications (2)

Publication Number Publication Date
CN112594076A true CN112594076A (en) 2021-04-02
CN112594076B CN112594076B (en) 2021-09-14

Family

ID=75195390

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011471866.2A Active CN112594076B (en) 2020-12-15 2020-12-15 Diesel engine minimum intake preheating power design method with low-temperature adaptability

Country Status (1)

Country Link
CN (1) CN112594076B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114139356A (en) * 2021-11-22 2022-03-04 北京理工大学 Design method for minimum preheating power of diesel engine heating pot with low-temperature adaptability
CN114491838A (en) * 2021-12-31 2022-05-13 北京理工大学 Method for calculating fuel spray ignition stagnation period in low-temperature environment

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5094198A (en) * 1991-04-26 1992-03-10 Cummins Electronics Company, Inc. Air intake heating method and device for internal combustion engines
US6161519A (en) * 1998-03-03 2000-12-19 Nissan Motor Co., Ltd. Combustion control device for diesel engine
JP2001227381A (en) * 2000-02-14 2001-08-24 Mazda Motor Corp Control device for diesel engine
JP2006046199A (en) * 2004-08-05 2006-02-16 Toyota Motor Corp Device and method for controlling start of diesel engine
WO2012099587A1 (en) * 2011-01-20 2012-07-26 International Engine Intellectual Property Company, Llc Fueling based on intake temperature
CN104727957A (en) * 2014-12-12 2015-06-24 西安电子科技大学 Piston type internal combustion engine control method dynamically changing volume of combustion chamber
CN105041517A (en) * 2015-07-13 2015-11-11 北京理工大学 Inlet air pressurizing and heating system of minitype internal combustion engine
CN110185559A (en) * 2019-06-29 2019-08-30 潍柴动力股份有限公司 A kind of inlet air heating control method, apparatus and system
CN111997808A (en) * 2020-08-20 2020-11-27 北京理工大学 Diesel engine and flame preheating plug thereof

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5094198A (en) * 1991-04-26 1992-03-10 Cummins Electronics Company, Inc. Air intake heating method and device for internal combustion engines
US6161519A (en) * 1998-03-03 2000-12-19 Nissan Motor Co., Ltd. Combustion control device for diesel engine
JP2001227381A (en) * 2000-02-14 2001-08-24 Mazda Motor Corp Control device for diesel engine
JP2006046199A (en) * 2004-08-05 2006-02-16 Toyota Motor Corp Device and method for controlling start of diesel engine
WO2012099587A1 (en) * 2011-01-20 2012-07-26 International Engine Intellectual Property Company, Llc Fueling based on intake temperature
CN104727957A (en) * 2014-12-12 2015-06-24 西安电子科技大学 Piston type internal combustion engine control method dynamically changing volume of combustion chamber
CN105041517A (en) * 2015-07-13 2015-11-11 北京理工大学 Inlet air pressurizing and heating system of minitype internal combustion engine
CN110185559A (en) * 2019-06-29 2019-08-30 潍柴动力股份有限公司 A kind of inlet air heating control method, apparatus and system
CN111997808A (en) * 2020-08-20 2020-11-27 北京理工大学 Diesel engine and flame preheating plug thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
刘福水等: "增压柴油机气道流量系数评价与稳流特性研究", 《农业机械学报》 *
端传凯: "增压柴油机压缩比控制优化研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 *
马玉坡: "低温环境下柴油喷雾与燃烧特性试验研究", 《中国博士学位论文全文数据库 工程科技Ⅱ辑》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114139356A (en) * 2021-11-22 2022-03-04 北京理工大学 Design method for minimum preheating power of diesel engine heating pot with low-temperature adaptability
CN114139356B (en) * 2021-11-22 2023-08-04 北京理工大学 Minimum preheating power design method for diesel heating pot with low-temperature adaptability
CN114491838A (en) * 2021-12-31 2022-05-13 北京理工大学 Method for calculating fuel spray ignition stagnation period in low-temperature environment

Also Published As

Publication number Publication date
CN112594076B (en) 2021-09-14

Similar Documents

Publication Publication Date Title
CN112594076B (en) Diesel engine minimum intake preheating power design method with low-temperature adaptability
Date et al. Research and development of the Honda CVCC engine
Scussel et al. The Ford PROCO engine update
Lee et al. High power performance with zero NOx emission in a hydrogen-fueled spark ignition engine by valve timing and lean boosting
Borman Mathematical simulation of internal combustion engine processes and performance including comparisons with experiment
US3842808A (en) Regenerative steam ignition internal combustion engine
CN110486151B (en) Dimethyl ether compression ignition type rotary engine and control method thereof
CN112377319B (en) Oil injection pressure control method for improving cold starting performance of diesel engine
Busch et al. Experimental and numerical studies of bowl geometry impacts on thermal efficiency in a light-duty diesel engine
Rather et al. A numerical study on the effects of exhaust gas recirculation temperature on controlling combustion and emissions of a diesel engine running on HCCI combustion mode
CN112594075B (en) Method for designing minimum intake preheating power of diesel engine with plateau adaptability
Sremec et al. Numerical investigation of injection timing influence on fuel slip and influence of compression ratio on knock occurrence in conventional dual fuel engine
Aktaş A 0/1-Dimensional Numerical Analysis of Performance and Emission Characteristics of the Conversion of Heavy-Duty Diesel Engine to Spark-Ignition Natural Gas Engine
CN103758641B (en) A kind of Engine Knock comprising external exhaust gas recirculation impact judges and the Forecasting Methodology in moment occurs
Shyani et al. A thermodynamic analysis of the use of exhaust gas recirculation in spark ignition engines including the second law of thermodynamics
Lestz et al. Emissions from a direct-cylinder water-injected spark-ignition engine
CN114239456B (en) Method and device for correcting oil supply rule of aviation gas turbine engine
CN112632867B (en) Design method and control method for minimum compression ratio of diesel engine
Grieshabe et al. Basic principles of the diesel engine
Cheng et al. Influence of exhaust gas recirculation on low-load diesel engine performance
Hairuddin et al. Predicting the combustion behaviour of a diesel hcci engine using a zero-dimensional single-zone model
Quader Single-Cylinder Engine Facility to Study Cold Starting-Results with Propane and Gasoline
Leman et al. Engine modelling of a single cylinder diesel engine fuelled by diesel-methanol blend
Allen et al. Heat balanced IC engine transition studies
CN113217211B (en) Diesel engine, and control system and method for starting diesel engine

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant